A web or weaved fabric comprises, as is well known, longitudinal warp threads and transversal weft threads. The warp threads preferably are continuous in order to be able to carry out the weaving in a continuous fashion on a jaquard-loom.
In order to obtain varying colors and patterns respectively in a fabric so far a certain combination of warp and/or weft threads, colored in various ways, has been put together in a way, that is time-consuming, complicated and results in extra costs. During the entire warp length this putting together has then been restricted to said combination and the pattern obtained thereby. A normal warp length is 500-2000 m. The colors and the patterns respectively then were visible through the color positions in the warp and the weft respectively and through the bonding patterns. This has resulted in, that during the weaving it has not been possible to change a certain patterned product more than at the most to a very insignificant extent.
In order to, in a weaved web, obtain many colors in a refined way it is necessary to weave in several web layers by means of so called double weaving, which is a technique, which results in a thick weave, which it is only possible to produce in a slow way. Also, it is necessary to weave large amounts of each pattern and color position of the pattern. The double weaving is used e.g. when it is desirble to conceal a colored thread on the rear side of the web in order to make it invisible on the front side.
EP-A1-0 692 562 relates to a method of simulating the true appearance of a web on a computer display device without first having to weave it. Considering the dynamic condition and behaviour of the warp and weft threads the already measured behavior of these threads can be corrected. A web pattern can also, according to this document, be detected and fed into data equipment and be shown on a display device respectively. The various threads can of course have different chosen colors. However, the drawbacks and deficiences mentioned above exist also in a product according to this document.
DE-A1-4 438 535 also starts from a fictitious pattern, which is divided into screen dots from three basic colors as well as black and white, each screen dot having at least the size of a weavable point. The web is then woven according to the jaquard process, various colors being obtained by combining various adjacent weaveable joints from said colors. This document starts with the additive color mixing, which is used in e.g. the printing field. This document does not mention, which threads are considered, e.g. no distinction is made between warp and weft threads and also, there is no assumption of any regularity whatsoever. Consequently, the practical weaving according to the suggested method seems to relate to just one already determined product, in which purely summarily savings can be made by limiting the number of starting colors. When a new product is to be produced, it appears to be inevitable to start from the beginning with anew arrangement of all the conditions. This method apparently is useful only for double weaving, in which the threads are concealed on the rear side. Thus, this method is also impaired by the already described drawbacks and deficiences.
Finally, U.S. Pat. No. 1,096,702 relates to a method of applying various colored warp threads with a minimal waste on a warp beam. The color arrangement is determined by the individual pattern, which is to be weaved, and has to be changed, when another pattern is to be used. Thus, also in this case the already described drawbacks and deficiences remain.